Conveyor Belt Upper Roller Dynamics for Back Line Pressure Reduction

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Solution Overview

Problem

Conveyor belts experience back line pressure issues due to friction and accumulation of articles, leading to damage and increased wear, which existing solutions like roller-top belts and zone accumulation systems either fail to fully address or require complex and costly setups.

Innovation Solution

A conveyor belt system featuring movable upper rollers with sloping slots that transition between forward and rearward positions, allowing them to disengage and re-engage with lower rollers to reduce back line pressure, utilizing a bearing surface for lower rollers and hinge joints for modular construction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If roller-top belts with freely rotatable rollers are used, then friction is reduced and back line pressure is lowered, but back line pressure cannot be decreased to zero

Engineering Contradiction:
Improveback line pressureVSAvoidcomplexity of additional belt and drive system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The upper rollers are made movable between a forward position (out of contact with lower rollers) and a rearward position (in contact with rotating lower rollers). This dynamic positioning allows the system to adapt to accumulation conditions, enabling the upper rollers to rotate rearward and reduce back line pressure to zero when articles back up, without requiring a separate driven belt system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses the weight of the accumulated articles themselves to drive the upper rollers into the rearward position through the sloping slots. The articles' weight applies force that pushes the upper rollers rearward onto the rotating lower rollers, which then rotate the upper rollers to reduce back line pressure. This self-actuating mechanism eliminates the need for external sensors or control systems.

Inventive Principle:
Principle #25Self-service

2Object-affected harmful factors

If zone accumulation with separately driven conveyors is used, then back line pressure is eliminated, but multiple drives and sensors are required which are costly and create transfer points where articles tip

Engineering Contradiction:
Improveback line pressureVSAvoidmultiple drives and sensors
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention combines the functions of multiple separately driven conveyors into a single continuously moving belt with movable upper rollers. The upper rollers can dynamically engage with the rotating lower rollers to create accumulation zones without requiring separate drive systems or transfer points between zones, eliminating the complexity of multiple drives and sensors while maintaining the back line pressure reduction benefit.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If upper rollers are held in fixed position, then article support is stable, but friction increases and back line pressure rises during accumulation

Engineering Contradiction:
Improvearticle support stabilityVSAvoidback line pressure
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The upper rollers transition from a fixed position to a dynamic position that allows movement between forward (out of contact) and rearward (in contact with rotating lower rollers) positions. This dynamic capability maintains article support stability when not accumulating while enabling back line pressure reduction when articles back up, resolving the contradiction between stability and friction reduction.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Effectively reduces back line pressure on accumulated articles by allowing upper rollers to rotate rearward and disengage, minimizing friction and wear while maintaining article positioning without additional drives or sensors, thus enhancing conveyor belt efficiency and reducing operational costs.

Implementation Method 1

The weight of an article on an upper roller applies a first force that pushes the upper roller forward toward the forward position

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

The drag between the article and the upper roller applies a second force that pushes the upper roller toward the rearward position

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

A bearing surface under the conveyor belt along the carryway provides a surface on which the lower rollers rotate as the belt advances forward along the carryway

Methodology Applied
Scientific EffectRolling contact: Roller

Data Source

PatentEP2704966B1Low back-pressure accumulation system
Publication Date: 2016.05.18 LAITRAM LLC
  • EP2704966B1 patent drawingFigure 1~2A

AI summary

A belt conveyor having upper article-supporting belt rollers that are rotated rearward by rotating lower belt rollers only when the articles are slowed or stopped from advancing with the belt. As the belt advances in a direction of travel, the lower rollers rotate by contact with a bearing surface underlying the belt. The upper rollers have axles whose ends are retained in slots that slope downward in the belt's direction of travel. The slots provide the upper rollers a range of positions between a forward position out of contact with the rotating lower roller and a rearward position contacting the lower roller, which rotates the upper roller rearward relieving back line pressure on accumulated articles.